1. Field of Invention
The present invention relates to a method and circuit for energizing and de-energizing an electric energy storage device to and from very high voltages, respectively.
2. Description of Prior Art
High-voltage, high-energy capacitors store electrical energy very efficiently, but there is no known means available to safely or effectively control the discharge of such terribly dangerous devices that are energized to several thousands of volts. Currently, one of the few methods for de-energizing a capacitor energized to a very high dc voltage employs gas-filled or vacuum tubes that are expensive, bulky, and inefficient. Such tubes are usually placed in series with the capacitor while an increasing dc voltage is applied. When the applied voltage reaches the breakdown voltage of the gas in the tube, arcing in the tube occurs and a tremendous surge of electrical current results that decreases rapidly over time. Once a gas-filled tube is turned on, there is no means to turn off the device to stop or impede current flow from the capacitor.
Capacitors, even when energized to very high dc voltages, have a relatively low energy density and yet the problems associated with controlling their charging and discharging are many. The amount of potential energy stored by an electrical storage device working on the principle of packing electrical charges into a small volume or mass is equal to the sum of all the energy and work associated with bringing each point charge into a position in the electrostatic or electric field. So it seems reasonable to assume that to increase the energy density and specific energy of an electric energy storage device of the future there would be great advantage to using as high an operating voltage as possible. However, since it is already such a cumbersome task to charge and discharge a relatively low energy density capacitor energized to a very high dc voltage, then the controlling of the charging and discharging of a novel high energy density, high specific energy electric storage device of the future in a safe, effective and efficient manner will be next to impossible. Therefore, the charging and discharging of an existing high voltage capacitor or a novel high voltage, high energy density electrical storage device of the future requires a switching method not now available which intermittently separates the storage device from the electrical load while small quantities of electrical current can be supplied to the load device since the tremendous surge of electrical current would most likely destroy electrical components in the load circuitry. Crude methods now in use today for charging and discharging high voltage electric energy storage devices require components with unreasonable power handling capabilities for withstanding the huge electrical current and large quantities of waste heat associated with a high-current discharge from any high voltage electric power source or electrical storage device. There is simply no electric switching method available at this time that can be utilized to control and limit the deadly and destructive electric current that arises when energizing or de-energizing any electric energy storage device that can operate at a high enough electric potential to be effective and efficient.